Rotary bolter



Sept. 30, 1924. Y 1,509,960

J. H LETZ ROTARY BOLTER Filed Nov. 20;, 1922 2 Sheets-Sheet. l

Jon/Iv #041. 0N0 L E By ysepta Q J. H. LETZ ROTARY BOLTER '2 Sheets-Sheet 2 Filed Nov. 20, 1.922

Patented Sept. 30, 1924.

UNITED STATES PATENT OFFICE.

JOHN HOLLAND LETZ, OF CROWN POINT, INDIANA, ASSIG-NOB TO LETZ MANUFACTUR- ING 00., A CORPORATION OF INDIANA.

ROTARY BOL'IER.

Application filed November 20, 1922. Serial No. 602,075.

To all whom it may concern:

Be it known that I, JOHN HOLLAND Law,

a citizen of the United States, and a resident of the city of Crown Point, in the county of Lake and State of Indiana, have invented certain new and useful Improvements in Rotary Bolters; and I do hereby declare that the following is a full, clear, and eXact description of the same, reference being had to the accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

My invention relates to an improved stationary screen, rotary bolter of special form and particularly adapted for use by the small user. My device is equally suited for a variety of uses depending only on the mesh of the screen used therewith.

It is a very important object of my invention to produce an easily and cheaply manufactured bolter that will be compact and easily portable, as well as adapted to use with almost any source of power available.

An important object is to produce a selfcontained unit for the purpose intended that receives the mixed material at one end, re-v jects the chaff, hulls or oversize at the other end and deposits the sifted material into a receptacle without attention from the user beyond feeding the material into the device.

It is highly desirable with a bolter for service of the class indicated that the wearing parts, such as the screen and bearings, be readily renewable and that the screen be changeable to a different mesh without calling in a factory man.

Because of the use such a mechanism is intended for, the points requiring attention or lubrication must be accessible and the whole machine must be readily disassembled and reassembled and this invention provides a device complying with these requirements.

It is a further important object of this invention to provide a mechanism of the class described wherein the screen is effectively reinforced.

It is still a further object of this invention to provide a bolter screen with reinforcements on each end which from a joint and stitl'ener when the screen is bent into the form of a cylinder.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is an elevation of my device.

Figure 2 is a slightly enlarged View of the charging end with the pulley removed.

Figure 3 is a longitudinal section on the line 3-3 of Figure 2.

Figure 4 is a cross section on the line H of Figure 3.

Figure 5 is an enlarged detail of the feeder screw.

Figure 6 is an enlarged detail of the shaft bearings.

Figure 7 is a plan view of the screen joint strlps.

As shown on the drawings:

The numeral 1 refers to the charging end piece having a charging opening 2, intended to limit the feed introduced into the bolter to the capacity of the bolter screen to prevent clogging, a boss 3 for the beat-er shaft bearing 4, an outwardly extending flange 5 to which the cover 6 is bolted, an inwardly extending circular flange 7 to which the screen 8 is bolted, and lugs or bosses 9 at its lower extremity to which a leg or standard 10 is attached. Inwardly projecting lugs or bosses 11 form a continuation of the flange 5 for holding the cover 6 near its extremities. The discharging end piece 12 differs only slightly in form from the charging end in that instead of the charging opening 2 it has a discharge opening 13 to which a spout 14 is attached for the discharge of material that fails to pass through the screen 8. Both ends are recessed above the bosses 3 so that the bearings f can be easily reached for oiling.

The screen 8 is bent around the flanges 7. Two strips of sheet metal 15 and 15 are fastened to the edges of the screen with interlocking joints. The edges of these strips overlap to form the screen joint and are bolted together. As shown in Fig. 7, the bolts fit in solts 2 in the edges of the strips to render assembling easier when the screen is placed in position after the assembly of the other parts. The strips 15 and 15 therefore act as stifi'eners and spacers at the top of the screen in connection with a flat steel bar 22.

As shown in Fig. l, a plurality of fiat bars 16 are also attached to the screen and rest on the flanges 7, being spaced approximately equidistant about the circumference of the flange to stiffen the screen.

The cover 6 is both a dust retainer, a strengthening member and a chute for the sifted material, as the edges are arranged to converge underneath the screen, being bolted to the bosses 11, which also support auxiliary ends 17 for the chute portion. The cover is bolted to the ends along the flanges 5.

The beater or stirrer portion consists of a beater shaft 18, journaled in the bearings l, which is revolved by any desired means, such as a pulley, crank or direct connection, to some source of power. The driving means may be applied at either end as desired. Starting with the entering or charging end, I have mounted first a short conveyor screw 19 to carry the material from the charging opening 21 into the screen portion proper,

and next a plurality of beater arms 20 having interlocking hubs and arranged in any desired form such as alternately at right angles. Each beater may consist of a plurality of inclined paddles. The last beater as shown is cut away at the outer tips to allow .it to project into the discharge casing to sweep the rejected material out to the discharge chute. The inclination of the paddles is in the same direction as the pitch of the conveyor screw so that they act as a continuation of the screw in carrying the material throughv the screen chamber. The beater shaft is located slightly below the axis of the screensothat the paddles will be closer to the screen at the bottom where most of the sifting'action occurs, thus tending to keep the screen free from clogging without actual contact to wear out the screen, and to permit the ground grain to drop away from the paddles more easily when reaching the top of the screen.

My device is very easy to assemble when the work is done according to the following method: The beatersor paddles and the conveyor screw are assembled on the shaft and the last one fastened thereto by any convenien-t method such as a key and keyway or a set screw through the hub. Then the bearings are added'to each end. The two end pieces may now be slipped over the bearings and the screen bent around the flanges 7 and the ends jointed together by the sheet metal strips. \Vith the screen in place, (bolts are inserted through the screen and flange) as well as through the joint strips. The addition of the legs and driving means completes the screener proper, the cover being necessary only as a dust shield and delivery chute for the screened material.

It will be noticed that my device presents a very compact appearance with no wasted space because of the use of most of the elements to accomplish several purposes, which naturally results in low manufacturing cost.

The operation of my device will be obvious from the, foregoing. The mixed material to be sifted, such as ground oats, ground corn or any combination of coarse and line material, is fed as required through the charging opening. If my device is used in connection with a grinding mill, a chute may be led from the mill to the charging opening so that rehandling avoided. In my device as illustrated, the shaft will be revolved clockwise when viewed from the pulley end. Such a direction of turn will cause the screw conveyor to feed the material onto the screen, where the beater arms or paddles agitate and at the same time carry it slowly along to the left. The speed of rotation of the shaft is such that only the rejected material such as husks or oversize n'latcrial is ejected by the last paddle into the discharge chute. The material sifted through the screen is directed by the chute formed by the outer cover into a receptacle placed beneath the bolter.

I am aware that numerous details of construction may be varied through a wide range without departing from the principlcs of this invention, and I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention:

1. In a device of the class described, a stationary cylindrical screen, sheet metal joining strips interlocking with the edges of said screen to reinforce the same, reinforcing bars arranged in contact with the screen below the center of said screen axis, end. members secured to said screen, charging and discharging chutes in said end members, a plurality of interlocking beater arms on said shaft whereby only one of which need be fastened to said shaft, and a one-piece cover over said screen fastened to the end members and formed into a collccting chute beneath said screen. I

2-. In a device of the class described. a stationary cylindrical screen, sheet metal joining strips interlocking with the edges of said screen to reinforce the same, reinforcing bars arranged in contact with the screen below the center of said screen axis, end members secured to said screen, charging and discharging chutes in said end members. a rotatable beater shaft supported in said end members, a plurality of interlocking beater arms on said shaft, the last banter arm being fastened to the shaft and adaptcd to scrape the rejected material into a discharge chute.

3. In a device of the class described, a slationary cylindrical v creen, sheet metal joining strips interlocking with the edges of said screen to reinforce the same, reinforcing bars arranged in contact With the screen below the center of said screen axis, end members secured to said screen, charging and discharging chutes in said end members, a rotatable beater shaft supported in said end members, a plurality of interlocking beater arms on said shaft, the last beater arm being fastened to the shaft and adapted to scrape the rejected material into a discharge chute, and a cover over said screen fastened to the end members and formed into a collecting chute beneath said screen.

4-. A rotary bolter comprising a stationary cylindrical screen, end members secured thereto, legs secured to said end members, a

charging hopper on one end member above the axis of the screen, a discharge chute on the other end member ada ted to receive rejected material pushed o the screen, a rotatable beater shaft mounted in said end members and disposed longitudinally in said screen, said beater shaft being adapted to agitate and convey material along the screen, and a cover constructed of a single sheet of material bent over the end members and formed into a collecting spout, beneath the screen. 1

In testimony whereof I have hereunto subscribed my name in the presence of tWo subscribing Witnesses:

JOHN HOLLAND LETZ. Witnesses:

WVILLIAM F. KITcHELL, JAcoB J. STEEG. 

